Aspects of the large-scale tropical atmospheric circulation

An account is given of a number of recent studies with idealised models who se aim is to further understanding of the large-scale tropical atmospheric circulation. Initial-value integrations with a model with imposed heating a re used to discuss aspects of the Asian summer monsoon, including constrain ts on cross-equatorial flow into the monsoon. The summer descent in the Med iterranean region and on the eastern sides of the summer subtropical anticy clones are seen to be associated with the monsoons to their east. An aqua-p lanet GCM is used to investigate the relationship between simple SST distri butions and tropical convection and circulation. The existence of strong eq uatorial convection and Hadley cells is found to depend sensitively on the curvature of the meridional profile in SST. Zonally confined SST maxima pro duce convective maxima centred to the west and suppression of convection el sewhere. Strong equatorial zonal flow changes are found in some experiments and three mechanisms for producing these are investigated in a model with imposed heating.